[kbuild-all] mm/vmalloc.c:472:1: warning: unused function 'compute_subtree_max_size'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 7f75285ca572eaabc028cf78c6ab5473d0d160be commit: 15ae144f77027db35fad168f24a1b9469dcf70a7 mm/vmalloc: switch to "propagate()" callback date: 8 months ago config: mips-randconfig-r023-20210414 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9829f5e6b1bca9b61efc629770d28bb9014dec45) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 15ae144f77027db35fad168f24a1b9469dcf70a7 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): mm/vmalloc.c:1300:6: warning: no previous prototype for function 'set_iounmap_nonlazy' void set_iounmap_nonlazy(void) ^ mm/vmalloc.c:1300:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void set_iounmap_nonlazy(void) ^ static compute_subtree_max_size(struct vmap_area ^ fatal error: error in backend: Nested variants found in inline asm string: ' .set push .set noat .set push .set arch=r4000 .if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/cmpxchg.h", .line = 80, $); 0x00 ) != -1)) : $))) ) && ( 0 ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif 1: ll $0, $2 # __xchg_asm .set pop move $$1, ${3:z} .set arch=r4000 sc $$1, $1 beqz $$1, 1b .set pop ' clang-13: error: clang frontend command failed with exit code 70 (use -v to see invocation) clang version 13.0.0 (git://gitmirror/llvm_project 9829f5e6b1bca9b61efc629770d28bb9014dec45) Target: mipsel-unknown-linux-gnu Thread model: posix InstalledDir: /opt/cross/clang-9829f5e6b1/bin clang-13: note: diagnostic msg: Makefile arch block certs crypto drivers fs include init ipc kernel lib mm net samples scripts security sound source usr virt vim +/compute_subtree_max_size +472 mm/vmalloc.c 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 467) 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 468) /* 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 469) * Gets called when remove the node and rotate. 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 470) */ 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 471) static __always_inline unsigned long 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 @472) compute_subtree_max_size(struct vmap_area *va) 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 473) { 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 474) return max3(va_size(va), 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 475) get_subtree_max_size(va->rb_node.rb_left), 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 476) get_subtree_max_size(va->rb_node.rb_right)); 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 477) } 68ad4a33043353 Uladzislau Rezki (Sony 2019-05-17 478) :::::: The code at line 472 was first introduced by commit :::::: 68ad4a3304335358f95a417f2a2b0c909e5119c4 mm/vmalloc.c: keep track of free blocks for vmap allocation :::::: TO: Uladzislau Rezki (Sony) <urezki(a)gmail.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org